The first shipments of a COVID-19 vaccine are expected to arrive next week in Colorado as part of a federal distribution plan that aims to deliver doses to front-line health care workers and long-term care residents before year’s end.

In addition to delivery of 46,800 doses of the Pfizer vaccine, the state plans to order 95,600 doses of the Moderna vaccine. Both vaccines are expected to be approved for emergency use by federal regulators by the end of this week, and both require two shots taken 18 to 20 days apart to be fully effective.

But Gov. Jared Polis made it clear during a news conference Wednesday that most of the general public will not receive the vaccine until the summer.

“Our main focus in creating the plan for Colorado is to ensure that we save the most lives and end the pandemic as soon as possible,” Polis said as he and other officials laid out the details Wednesday.

Health care workers and first responders dealing directly with COVID-19 patients, as well as residents of long-term care centers, such as nursing homes, are considered most at risk and will be among the first to receive the vaccine as part of the state’s Phase 1A distribution plan.

Firefighters, police officers and health care workers who do not deal directly with COVID-19 patients are next in line to receive the shot as part of Phase 1B.

But the vaccination timeline suggests the state doesn’t anticipate receiving enough vaccines in the short term for some of those most at risk of contracting the virus, including people who are 65 or older and people with pre-existing conditions such as chronic lung disease, who fall into the Phase 2 spring category.

The state has identified 140,000 people who qualify as Phase 1A health care workers who should be vaccinated, but the first shipment of the Pfizer vaccine will be enough for only one-third of that number, said Liane Jollon, executive director of San Juan Basin Public Health.

Long-term care residents under Phase 1A will likely not be vaccinated until February, Jollon said.

Most of the general public will be vaccinated by the summer, or Phase 3.

“We’re not anywhere near out of the woods,” Jollon said. The public health department will continue to investigate COVID-19 cases and spread for at least another six months.

Brian Devine, deputy incident commander for San Juan Basin Public Health’s COVID-19 response, said vaccine planning and distribution will add to the public health agency’s workload.

The vaccine will not be available widely or quickly enough to slow community spread, which means contact tracing and testing must continue at the same rate it is currently being done, Devine said.

The vaccine will not curb SJBPH’s workload until next year, because it is “going to take a while to vaccinate everyone who needs to be and wants to be,” he said.

“It is unprecedented in the history of public health to vaccinate this many people this quickly,” he said.

The vaccination roll-out plan includes decisions made at the state level, but SJBPH is responsible for coordinating the delivery of vaccine doses to nursing homes on the right days at the right temperature.

Devine and others at the health department are prepping for what he anticipates will be a “wild ride over the next couple of weeks.”

The first vaccinations in Colorado will be for health care workers to keep hospitals working at top capacity, Devine said. The number of staff members available to care for patients has become a growing issue as nurses and doctors at Mercy Regional Medical Center become ill.

But hospitalizations have slowed in the past few days, and with the first shipments of the vaccine coming, Devine said La Plata County is “not too far off from making a dent and getting back to normal.”

However, wearing a mask, washing hands, self-isolating and avoiding indoor gatherings continue to be vital to successfully beating the virus.

Watching for symptoms and getting tested is just as important, Devine said. But some Durango residents have questioned the validity of the PCR COVID-19 test, often considered the “gold standard” in testing.

According to the Colorado Department of Public Health and Environment, the PCR test, or the swab that goes up a patient’s nostrils, has a “very high specificity and sensitivity, which means it only detects COVID-19 and that it can detect small amounts of the virus.”

“It detects strands of viral RNA from this specific virus,” Devine said. “It has a very low false positive rate.”

Other types of COVID-19 testing, such as a rapid antigen test, can quickly detect fragments of proteins found on or within the virus that causes COVID-19 from a swab of the nasal cavity.

Results can be obtained anywhere from 15 minutes to two hours after the test is taken, and the test itself is less expensive. But the test is “not as sensitive as a PCR test,” according to a spokeswoman for the state health department.

But traces of COVID-19 may not exist in the nasal cavity by the time someone with symptoms is tested. As a respiratory virus, it may have traveled to the lungs, Devine said.

A positive rapid antigen test should be treated as a positive result, but a PCR test might be needed to confirm a negative rapid antigen test, according to the CDPHE.

A serological test is a blood test that looks for antibodies and detects the body’s immune response to the virus, instead of detecting the virus itself. The tests are used to determine if someone has had previous exposure to COVID-19, but it does not reliably determine if a patient is currently infected with the virus and can spread it to others.

“Testing is one of the most important things we do – it is the centerpiece of containing this virus,” Devine said. Testing determines which people in the community need to isolate to contain the spread.

Funding for SJBPH’s response to the virus has come primarily from the Coronavirus Aid, Relief and Economic Security Act, a bill passed by U.S. Congress in the spring in response to the public health and economic impact of the global pandemic.

Through the end of October, SJBPH had spent more than $1.1 million on the response to COVID-19 in Archuleta and La Plata counties, the two counties it serves. About $950,000 was funded by the CARES Act.

“I expect our monthly costs went up in November, and will be even higher in December ... due to increased need for testing, disease investigation and control, community transmission control, enforcement, vaccine planning, and medical surge as cases increase,” Devine said in an email.

But funding from the act expires at the end of the year.

Devine said the public health agency received funding from the Centers for Disease Control and Prevention, money it has set aside for when the CARES Act funding expires. Almost $1 million was allocated to the local health department from the state.

The CDPHE covers laboratory costs from COVID-19 test processing using the CARES Act, as well. The state Legislature allocated $100 million last week for the state’s continued public health response to COVID-19.

“For next year, we reallocated a lot of general funding for communicable disease,” Devine said. “But that means less funding will be available for other services.”

An earlier version of this story gave an incorrect timeline for when Gov. Jared Polis said the vaccine would be available to the general public. The vaccine will be available to the general public this summer, he said.